將Delphi作為ASP.NET的腳本語言

2024-07-10 13:12:02

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   將delphi視為腳本語言

   支持asp.net的第一件事是讓asp.net將delphi視為腳本語言，讓asp.net能夠為各種asp文件類型調用delphi的.net編譯器。

   asp.net要在iis虛路徑的根目錄下尋找web.config文件。下面是asp.net中使用delphi作腳本語言的web.config配制文件內容：

   <configuration>
   <system.web>
   <compilation debug="true">
   <assemblies>
   <add assembly="delphiprovider" />
   </assemblies>
   <compilers>
   <compiler language="delphi" extension=".pas"
   type="borland.delphi.delphicodeprovider,delphiprovider" />
   </compilers>
   </compilation>
   </system.web>
   </configuration>

   關于web配制文件的詳情請參msdn：
   http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconformatofconfigurationfiles.asp

   在我的機器(win2k pro)上測試delphi對asp.net的支持。要增加一個虛路徑來安放delphi腳本，我把這個路徑名定為"vslive"。

   在我的機器配制文件上作了這個小改動后就可以來看asp.net是如何將delphi視為腳本語言的。

   在asp.net中使用delphi代碼
   首先編寫一個簡單應用來確認我們的delphi支持配制是正確的。下面是editdemo.aspx文件的代碼，有一個文本輸入框，一個按鈕。按鈕事件觸發顯示輸入框內容。

   <html>
   <script language="delphi" runat="server">
   procedure buttonclick(sender: system.object; e: eventargs);
   begin
   message.text := edit1.text;
   end;
   </script>
   <body>
   <form runat="server">
   <asp:textbox id="edit1" runat="server"/>
   <asp:button text="click me!" onclick="buttonclick" runat="server"/>
   </form>
   <p><b><asp:label id="message" runat="server"/></b></p>
   </body>
   </html>

   可以看到，asp按鈕對象的onclick事件觸發delphi的buttonclick過程，而delphi程序里卻使用了asp對象label message和text box edit1。雖然在delphi過程中沒有定義asp的二個變量，delphi代碼卻能找到它們。這是因為腳本中含有的delphi服務模塊能夠產生相應的delphi代碼。

   現在可以用本地瀏覽器來瀏覽這個網頁了。因為我把腳本放在"vslive"虛路徑，所以打開：
   http://localhost/vslive/editdemo.aspx.

   以下是編譯之后形成的delphi代碼，代碼產生webform：

//------------------------------------------------------------------------------
  // <autogenerated>
  // 本代碼由一個工具生成
  // 運行版本：1.0.3705.209
  //
  // 修改本文件將導致異常行為并丟失生成的代碼。
  // </autogenerated>
  //------------------------------------------------------------------------------

  unit asp;

  interface

  uses system.collections, system.collections.specialized, system.configuration,
   system.text, system.text.regularexpressions, system.web, system.web.caching,
   system.web.sessionstate, system.web.security, system.web.ui, system.web.ui.webcontrols,
   system.web.ui.htmlcontrols, system.globalization;

  var
   editdemo_aspx___autohandlers: integer;
   editdemo_aspx___intialized: boolean = false;
   editdemo_aspx___filedependencies: system.collections.arraylist;
  type
   editdemo_aspx = class(system.web.ui.page, system.web.sessionstate.irequiressessionstate)
   protected
   edit1: system.web.ui.webcontrols.textbox;
   __control3: system.web.ui.webcontrols.button;
   __control2: system.web.ui.htmlcontrols.htmlform;
   message: system.web.ui.webcontrols.label;
   procedure buttonclick(sender: system.object; e: eventargs);
   public
   constructor create;
   function get_autohandlers: integer; override;
   function get_applicationinstance: system.web.httpapplication; virtual;
   function get_templatesourcedirectory: system.string; override;
   procedure set_autohandlers(value: integer); override;
   protected
   property autohandlers: integer read get_autohandlers write set_autohandlers;
   property applicationinstance: system.web.httpapplication read get_applicationinstance;
   public
   property templatesourcedirectory: system.string read get_templatesourcedirectory;
   private
   function __buildcontroledit1: system.web.ui.control;
   function __buildcontrol__control3: system.web.ui.control;
   function __buildcontrol__control2: system.web.ui.control;
   function __buildcontrolmessage: system.web.ui.control;
   procedure __buildcontroltree(__ctrl: system.web.ui.control);
   protected
   procedure frameworkinitialize; override;
   public
   function gettypehashcode: integer; override;
   end;

  implementation


   procedure editdemo_aspx.buttonclick(sender: system.object; e: eventargs);
   begin
   message.text := edit1.text;
   end;
   constructor editdemo_aspx.create;
  var
   dependencies: system.collections.arraylist;
  begin
   inherited create;

   if (asp.editdemo_aspx___intialized = false) then
   begin
   dependencies := system.collections.arraylist.create;
   dependencies.add('d:/vslive/editdemo.aspx');
   asp.editdemo_aspx___filedependencies := dependencies;
   asp.editdemo_aspx___intialized := true;
   end;
   self.server.scripttimeout := 30000000;
  end;

  function editdemo_aspx.get_autohandlers: integer;
  begin
   result := asp.editdemo_aspx___autohandlers;
  end;

  function editdemo_aspx.get_applicationinstance: system.web.httpapplication;
  begin
   result := self.context.applicationinstance as system.web.httpapplication;
  end;

  function editdemo_aspx.get_templatesourcedirectory: system.string;
  begin
   result := '/vslive';
  end;

  procedure editdemo_aspx.set_autohandlers(value: integer);
  begin
   asp.editdemo_aspx___autohandlers := value;
  end;

  function editdemo_aspx.__buildcontroledit1: system.web.ui.control;
  var
   __ctrl: system.web.ui.webcontrols.textbox;
  begin

   __ctrl := system.web.ui.webcontrols.textbox.create;
   self.edit1 := __ctrl;
   __ctrl.id := 'edit1';
   __ctrl.width := system.web.ui.webcontrols.unit.parse('300px', system.globalization.cultureinfo.invariantculture);
   result := __ctrl;
  end;

  function editdemo_aspx.__buildcontrol__control3: system.web.ui.control;
  var
   __ctrl: system.web.ui.webcontrols.button;
  begin

   __ctrl := system.web.ui.webcontrols.button.create;
   self.__control3 := __ctrl;
   __ctrl.text := 'click me!';
   __ctrl.add_click(self.buttonclick);
   result := __ctrl;
  end;

  function editdemo_aspx.__buildcontrol__control2: system.web.ui.control;
  var
   __parser: system.web.ui.iparseraccessor;
   __ctrl: system.web.ui.htmlcontrols.htmlform;
  begin

   __ctrl := system.web.ui.htmlcontrols.htmlform.create;
   self.__control2 := __ctrl;
   __parser := __ctrl as system.web.ui.iparseraccessor;
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' '));
   self.__buildcontroledit1;
   __parser.addparsedsubobject(self.edit1);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' '));
   self.__buildcontrol__control3;
   __parser.addparsedsubobject(self.__control3);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' '));
   result := __ctrl;
  end;

  function editdemo_aspx.__buildcontrolmessage: system.web.ui.control;
  var
   __ctrl: system.web.ui.webcontrols.label;
  begin

   __ctrl := system.web.ui.webcontrols.label.create;
   self.message := __ctrl;
   __ctrl.id := 'message';
   result := __ctrl;
  end;

  procedure editdemo_aspx.__buildcontroltree(__ctrl: system.web.ui.control);
  var
   __parser: system.web.ui.iparseraccessor;
  begin
   __parser := __ctrl as system.web.ui.iparseraccessor;
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create('<html>'#13#10' '));
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' <body>'#13#10' '));
   self.__buildcontrol__control2;
   __parser.addparsedsubobject(self.__control2);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' <p><b>'));
   self.__buildcontrolmessage;
   __parser.addparsedsubobject(self.message);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create('</b></p>'#13#10' </body>'#13#10'</html>'#13#10));
  end;

  procedure editdemo_aspx.frameworkinitialize;
  begin
   self.__buildcontroltree(self);
   self.filedependencies := asp.editdemo_aspx___filedependencies;
   self.enableviewstatemac := true;
  end;

  function editdemo_aspx.gettypehashcode: integer;
  begin
   result := -764444463;
  end;

  end.

  注意：這里介紹的是delphi的.net編譯器功能的預覽。正式發布的delphi 7生成的代碼與上面將有顯著不同。本文僅是示例說明如何在asp.net中使用delphi及其功能。

   更高技術的網頁
  asp.net的一些控件遠比html控件要更加智能化。其中之一就是日歷(calendar)控件。

  以下代碼是calendar.aspx中的一部分。代碼提供二種方法讓控件設置日期：
  　瀏覽日歷然后選擇日期；
  　按照日期格式輸入日期，確認選擇。這種方法由.net的convert類支持。

  <script language="delphi" runat="server">
  procedure calendar1selected(sender: system.object; e: eventargs);
  begin
   label1.text := 'delphi for .net says you picked ' + calendar1.selecteddate.tostring('d');
  end;

  procedure button1click(sender: system.object; e:eventargs);
  begin
   calendar1.visibledate := system.convert.todatetime(edit1.text);
   label1.text := 'delphi for .net says you set ' + calendar1.visibledate.tostring('d');
  end;
  </script>

  <body >
   <form runat="server">
   <center>
   <h1>delphi for .net running in asp.net</h1>
   <p>please pick a date</p>
   <asp:calendar id="calendar1" runat="server" forecolor="#0000ff" backcolor="#ffffcc"
   onselectionchanged="calendar1selected">
   <todaydaystyle font-bold="true"/>
   <nextprevstyle forecolor="#ffffcc"/>
   <dayheaderstyle backcolor="#ffcc66"/>
   <selecteddaystyle forecolor="black" backcolor="#ccccff"/>
   <titlestyle font-size="14pt" font-bold="true" forecolor="#ffffcc" backcolor="#990000"/>
   <othermonthdaystyle forecolor="#cc9966"/>
   </asp:calendar>
   <p><asp:textbox id="edit1" width=200 runat="server"/>
   <asp:button text="set date" id="button1" onclick="button1click" runat="server" />
   </p>
   <p><asp:label id="label1" runat="server"/></p>
   </center>
   </form>
  </body>

  在日歷上選擇日期觸發onselectionchanged事件，調用delphi的calendar1selected()過程。
  輸入日期，點擊"set data"按鈕觸發button1click事件，調用delphi的button1click()過程。

  數據處理
  現在通過日歷的日期選擇來選擇顯示數據庫數據。在這個asp.net delphi網頁上，增加一個datagrid和一個textbox，前者顯示數據庫數據，后者輸入要顯示的數據庫域。

  <%@import namespace="system.data"%>
  <%@import namespace="system.data.sqlclient"%>

  <script language="delphi" runat="server">
  const
   prodname = 'delphi for .net';
   dispfields = 'orderid, customerid, shipname, shipcity, shipcountry';

  procedure dateselected(sender: system.object; e: eventargs);
  begin
   label1.text := prodname + ' says you picked ' + calendar1.selecteddate.tostring('d');
   datagrid1.datasource := getorders(calendar1.selecteddate);
   datagrid1.databind;
  end;

  procedure button1click(sender: system.object; e:eventargs);
  begin
   calendar1.visibledate := system.convert.todatetime(edit1.text);
   label1.text := prodname + ' says you set ' + calendar1.visibledate.tostring('d');
  end;

  procedure button2click(sender: system.object; e:eventargs);
  begin
   displayfields.text := dispfields;
  end;

  function getorders(date : datetime) : dataset;
  var
   adapter : sqldataadapter;
  begin
   adapter := sqldataadapter.create(
   'select ' + displayfields.text + ' from orders '+
   'where orderdate = ''' + date.tostring('d')+'''',
   'server=(local);database=northwind;trusted_connection=yes');
   result := dataset.create;
   adapter.fill(result);
  end;

  </script>

  <body >
   <form runat="server">
   <h1><%=prodname %> with a calendar, datagrid, & sqlclient in asp.net</h1>
   <table>
   <tr valign="top"><td>
   <p><b>pick a date</b></p>
   <asp:calendar id="calendar1" runat="server" forecolor="#0000ff" backcolor="#ffffcc"
   onselectionchanged="dateselected">
   <todaydaystyle font-bold="true"/>
   <nextprevstyle forecolor="#ffffcc"/>
   <dayheaderstyle backcolor="#ffcc66"/>
   <selecteddaystyle forecolor="black" backcolor="#ccccff"/>
   <titlestyle font-size="14pt" font-bold="true" forecolor="#ffffcc" backcolor="#990000"/>
   <othermonthdaystyle forecolor="#cc9966"/>
   </asp:calendar>
   <p><asp:textbox id="edit1" width=150 runat="server"/>
   <asp:button text="set date" id="button1" onclick="button1click" runat="server" />
   </p>
   </td><td valign="top">
   <p><b>display fields:</b> <asp:textbox id="displayfields"
   text="orderid, customerid, shipname, shipcity, shipcountry" width=500 runat="server"/>
   <asp:button text="reset fields" id="button2" onclick="button2click" runat="server" /></p>
   <asp:datagrid id="datagrid1" runat="server" bordercolor="#ffcc66" forecolor="#0000ff">
   <headerstyle forecolor="#ffffcc" backcolor="#990000"/>
   </asp:datagrid>
   </td></tr></table>
   <p><asp:label id="label1" runat="server"/></p>
   </form>
  </body>

  每當用戶點擊日歷選擇日期時，就觸發onselectionchanged事件，調用dateselected()函數。
  在getorders函數中，數據庫的連接由命名空間定義的sqlclient實現，數據庫是ms sql 2000的示范庫northwind。sqldataadapter將查詢結果安裝到datagrid中，顯示出數據表格，如附圖。

  改變域輸入框的域名，再點擊日歷，就得到不同的結果。

  這就是日歷驅動的數據庫查詢系統，由delphi for .net與asp.net共同完成。

  結語
  本文試圖簡略說明在asp.net中應用delphi是如何方便。
  請記住，本文示例是delphi 7的預覽示例，正式版本的結果也許不完全如此，當然也許就是如此。